[LUCENE-2779] Use ConcurrentHashMap in RAMDirectory

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.1, 4.0-ALPHA
• Component/s: core/store
• Lucene Fields: New, Patch Available
• Assignee: Shai Erera
• Reporter: Shai Erera
• Created: 25/Nov/10 17:28
• Updated: 28/Aug/22 12:36
• Resolved: 01/Dec/10 15:06

Description

RAMDirectory synchronizes on its instance in many places to protect access to map of RAMFiles, in addition to updating the sizeInBytes member. In many places the sync is done for 'read' purposes, while only in few places we need 'write' access. This looks like a perfect use case for ConcurrentHashMap

Also, syncing around sizeInBytes is unnecessary IMO, since it's an AtomicLong ...

I'll post a patch shortly.

Issue Links

• is related to: HARMONY-6681 AbstractCollection.toArray() and AbstractCollection.toArray(T[]) are broken for concurrently modified collections like ConcurrentHashMap.keySet()